The full flag featuring the sun is called the Official Ceremonial Flag (Spanish: Bandera Oficial de Ceremonia). The flag without the sun is considered the Ornamental Flag (Bandera de Ornato). While both versions are equally considered the national flag, the ornamental version must always be hoisted below the Official Ceremony Flag. In vexillological terms, the Official Ceremonial Flag is the civil, state and war flag and ensign, while the Ornamental Flag is an alternative civil flag and ensign.

The flag of Argentina was created by Manuel Belgrano during the Argentine War of Independence. While in Rosario he noticed that both the royalist and patriotic forces were using the same colors, Spain's yellow and red. After realizing this, Manuel Belgrano created the Cockade of Argentina, which was approved by the First Triumvirate on February 18, 1812. Encouraged by this success, he created a flag of the same colours nine days later. It used the colors that were used by the Criollos during the May Revolution in 1810. However, recent research and studies would indicate that the colors were chosen from the Spanish Order of Charles III symbolizing the allegiance to the rightful, and then captive King Ferdinand VII of Spain. Most portraits about the creation or first uses of the flag show the modern design of it, but the flag of Macha, a very early design kept at the House of Freedom in Sucre, Bolivia was instead a vertical triband with two white bands and a light blue one in the middle.[1] The flag was first flown, for the soldiers to swear allegiance to it, on 27 February 1812, on the Batería Libertad (Liberty Battery), by the Paraná River. On that day, Belgrano said the following words:

Soldiers of the Fatherland, we have heretofore had the glory of wearing the national cockade; there (pointing to the Independence battery), on the Independence Battery, where our Government has recently had the honor of bestowing it upon, shall our weapons enlarge their glory. Let us swear to defeat our enemies, internal and external, and South America will become the temple of Independence and Freedom. In testament that you so swear it, say with me: LONG LIVE THE FATHERLAND! (after the oath) "Lord Captain and troops chosen for the first time for the Independence Battery: go, take possession of it and fulfill the oath you have just sworn today.[2]

Belgrano dispatched a letter addressed to the First Triumvirate, informing them of the newly created flag. However, unlike with the cockade, the Triumvirate did not accept the use of the flag: the international policy by the time was to state that the government was ruling on behalf of Ferdinand VII king of Spain captive of Napoleón, whereas the creation of a flag was a clear independentist act. Thus, the triumvirate sent a warning to Belgrano not to fight under the flag, but by the time the reply had arrived, Belgrano had moved to the north, following the previous orders that requested him to strengthen the patriotic position in the Upper Peru after the defeat of Juan José Castelli at the Battle of Huaqui. Meanwhile, the flag was hoisted for the first time in Buenos Aires atop the Saint Nicholas of Bari Church on August 23, 1812; where nowadays the Obelisk of Buenos Aires is located. Still not knowing about the Triumvirate's refusal, Belgrano raised the flag at San Salvador de Jujuy and had it blessed by the local church on the second anniversary of the May Revolution. Belgrano accepted the orders from the Triumvirate by time they arrived to Salta and ended using the flag. As soldiers had already made oaths to the new flag, Belgrano said that he was saving it for the circumstance of a great victory.

The First Triumvirate was later replaced by the Second Triumvirate, with a more liberal ideology, who called the Asamblea del Año XIII. Despite being one of the original goals, it did not declare independency, and so neither approve the use of a national flag; nevertheless, the flag made by Belgrano was authorized to be used as a War flag. The first oath to the newly approved flag was on February 13, 1813, next to the Salado River, which as also known since then as "Río Juramento" ("Oath River"). The first battle fought with the approved flag was the Battle of Salta, a decisive patriotic victory that achieved the complete defeat of royalist Pío Tristán.

The flag would be finally declared the National flag by the Congress of Tucumán on July 20, 1816, shortly after the declaration of independence. The proposal was made by the deputy Juan José Paso and the text written by the deputy of Charcas, José Serrano. On February 25, 1818, the Congress (now working at Buenos Aires) included the Sun of May in the War flag, after the proposal of deputy Chorroarín. The sun was copied after the one that the first Argentine coin featured in 1813. It was subsequently decided to be part of the regular flag afterwards, and thus the sun no longer represents war.

The Argentine flag flying for the first time over a coastal battery on the shores of the Paraná, 27 February 1812

José de San Martín was aware of the new flag, but did not employ it during the Crossing of the Andes in 1817. Being a joint operation of both Argentine and Chilean forces, he thought that a new flag would be a better idea than using either the Argentine or Chilean flag. This led to the creation of the Flag of the Andes, used in the Crossing. This flag is currently used as provincial flag by the Mendoza province.

On June 8, 1938, president Roberto Ortiz sanctioned the national law Nº 12.361 declaring June 20 "Flag Day", a national holiday. The date was decided after the anniversary of Belgrano's death in 1820. In 1957 the National Flag Memorial (a 10,000 m² monumental complex) was inaugurated in Rosario to commemorate the creation of the flag, and the official Flag Day ceremonies have been customarily conducted in its vicinity since then.

In 1978 it was specified, among other measurements, that the Official Ceremony Flag should be 1.4 meters wide and 0.9 meters high, and that the sun must be embroidered.

Popular belief attributes the colors to those of the sky, clouds and the sun; some anthems to the flag like "Aurora" or "Salute to the flag" state so as well. However, historians usually disregard such idea, and attribute them to loyalty towards the House of Bourbon.[citation needed]

From 1978, the flag's official proportions are 9:14, and its official size is 0.9 by 1.4 meters. It features three stripes alternating cerulean blue - white. Each stripe is 30 centimeters high.[citation needed] In the center stripe there is an emblem known as the Sun of May (Spanish: Sol de Mayo), a golden sun. Historian Diego Abad de Santillán claimed that the Sun of May was a representation of the Inca sun god Inti.[3]

In 1978 the sun color was specified to be golden yellow (amarillo oro), to have an inner diameter of 10 cm, and an outer diameter of 25 cm (the diameter of the sun equals the height of the white stripe. The sun's face is of its height). It features 32 rays, 16 undulated and 16 straight, in alternation and from 1978 it must be embroidered in the "Official Flag Ceremony".[citation needed]

The French privateer Louis-Michel Aury used the Argentine flag as a model for the blue-white-blue flag of the first independent state in Central America, which was created 1818 in Isla de Providencia, an island off the east coast of Nicaragua. This state existed until approximately 1821, before the Gran Colombia took over control of these islands. Somewhat later (1823) this flag was again the model for the flag of the United Provinces of Central America,[4][5][6] a confederation of the current Central American states of Guatemala, Honduras, El Salvador, Nicaragua and Costa Rica, which existed from 1823 to 1838. After the dissolution of the Union, the five countries became independent, but even today all of these states except Costa Rica use flags of blue-white-blue stripes (the Costa Rican flag has a red stripe superimposed on the white one - the red stripe was added to incorporate all the colors of the French flag). The Argentine flag also inspired the flags of Uruguay and Paraguay.

As Flag Day is celebrated on June 20, the following pledge is recited to students nationwide on this day by their respective school principals or grade level advisers. In large towns where students are gathered en masse, the pledge is taken by the local town or city executive, preceded by words of advice and honor to the memory of its creator, Manuel Belgano, using the following or similar formulas:

Summons:Childen/Students, God cannot permit this white and sky-blue flag to be carried in the triumphal carts of the victors of this earth.

Children/Students, this glorious Flag represents the Fatherland of the Argentinians. I ask you all to promise to produce your most sincere and respectful homage, to want it and form it with immense love, from the dawn of the life a fervent and indelible cult in your hearts; preparing yourselves from the school to practice to its time, with all purity and honesty, the noble virtues inherent in citizenship, studying with determination the history of our country and that of its big benefactors in order to continue its luminous traces and to end also of honoring the Flag and of which there should never get depressed in your souls the delicate and generous love feeling to the Fatherland. In a word: do you promise that what should be in the measurements of your forces that the Flag of Argentina flames forever exceeds our walls and fortitude, on top of the masts of our ships and at the head of our legions and so that the honor should be its breath, the glory its aurora, the justice its company?

Response:"Yes, we promise!"
(either using the Bellamy salute or using the hand over the heart gesture, if not all stand at attention)

Summons:Childen/Students, in the sunrise of our freedom, Manuel Belgrano created this flag, the very symbol of our fatherland, the Republic of Argentina.

Children/Students, It is the symbol of our free sovereignty, which makes it sacred to the men and women and to all the peoples of the world. It was convoked by the exercise of our duties and our rights, to respect the laws and institutions. It is the expression of our history forged with the hope and the efforts of millions of men and women, those who were born in our land and those who came to settle it under our flag and our Constitution. It represents our land and seas, our rivers and forests, our plains and mountains, the efforts of its inhabitants, their dreams and achievements. It symbolizes our present, in which, day to day, we must build democracy that enables us, and conquer the knowledge that frees us; and our future, for our children and the successive generations of Argentines.

Children/Students, therefore, Do you promise to defend, respect, and love it, with fraternal tolerance and respect, studying with determination, committing to be free and honest citizens, in solidarity accepting their differences to all who populate in our land and manifest, in each and every one of our actions, these permanent and inalienable values?

Response:"Yes, we promise!"
(either using the Bellamy salute or using the hand over the heart gesture, if not all stand at attention)